v0.5.0

Logging through Gravity Forms' logging framework

Decisions are now logged via Gravity Forms' own logging framework instead of a custom toggle + error_log. The plugin appears under Forms → Settings → Logging as ALTCHA for Gravity Forms, with a per-add-on level (off / errors only / all) and a downloadable log file. Failures (fail / blocked / spam) log at error level, passes at debug.

• Drops the enable_logging setting and the genero/gravityforms_altcha/logging filter — GF's Logging UI controls verbosity.
• Keeps the genero/gravityforms_altcha/log action for custom routing (Sentry, Query Monitor).
• Privacy unchanged: IPs as a salted hash, emails as the domain only.

See #4.